I know this was probably asked 100 times. Why on some 510 attys are there ones with a washer in the inside and some just have the metal Brillo material?? To me it seems as though the ones with the washers in them suck. Maybe it is just me. Fill me in!!!!
Different manufacturers. The washer is an SLB510, the "brillo" is a Joye 510. The washer ones seem to be best on higher capacity batts, like the 14500
mods, since they have slightly higher resistance than the Joyes. Joyes supposedly perform better on the regular batts or mega batts, which put less voltage on the atty coil. Some love the washer ones. Some don't. If you are a regular or mega batt user, I would stick with Joyes (also called Dura, Titan, Yeti). Unless these names are used in a website, do not assume they are Joyes.